View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *  http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.any23.extractor.xpath;
19  
20  import java.util.Locale;
21  
22  import org.eclipse.rdf4j.model.Value;
23  import org.eclipse.rdf4j.model.impl.SimpleValueFactory;
24  
25  /**
26   * Represents a <i>Quad</i> object <i>template</i>.
27   *
28   * @author Michele Mostarda (mostarda@fbk.eu)
29   */
30  public class TemplateObject extends Term {
31  
32      /**
33       * Supported object types.
34       */
35      public enum Type {
36          URI, BNODE, LITERAL
37      }
38  
39      /**
40       * Current template type.
41       */
42      private final Type type;
43  
44      /**
45       * Constructor.
46       *
47       * @param type
48       *            object template type.
49       * @param value
50       *            internal value.
51       * @param isVar
52       *            if <code>true</code> it the given <code>value</code> will be resolved with the variable value.
53       */
54      public TemplateObject(Type type, String value, boolean isVar) {
55          super(value, isVar);
56          if (type == null) {
57              throw new NullPointerException("object type cannot be null.");
58          }
59          this.type = type;
60      }
61  
62      @Override
63      protected Value getValueInternal(String value) {
64          switch (type) {
65          case URI:
66              return createIRI(value);
67          case BNODE:
68              return SimpleValueFactory.getInstance().createBNode(value);
69          case LITERAL:
70              return SimpleValueFactory.getInstance().createLiteral(value);
71          default:
72              throw new IllegalStateException();
73          }
74      }
75  
76      private Value createIRI(String value) {
77          try {
78              return SimpleValueFactory.getInstance().createIRI(value);
79          } catch (IllegalArgumentException iae) {
80              throw new IllegalArgumentException(
81                      String.format(Locale.ROOT, "Expected a valid IRI for object template, found '%s'", value), iae);
82          }
83      }
84  
85      @Override
86      public String toString() {
87          final String superStr = super.toString();
88          switch (type) {
89          case URI:
90              return "<" + superStr + ">";
91          case BNODE:
92              return "_:" + superStr;
93          case LITERAL:
94              return "'" + superStr + "'";
95          default:
96              throw new IllegalStateException();
97          }
98      }
99  
100 }